Are you sure that is a genuine Mullard? The print does not look like any Mullard I have seen before. The box and the wrapping look genuine, though. What is the etch code? Does it have seams on the top of the glass?

Are you sure that is a genuine Mullard? The print does not look like any Mullard I have seen before. The box and the wrapping look genuine, though. What is the etch code? Does it have seams on the top of the glass?

There are four seams on the top-glass (like the stars on a compass).
The 'Blackburne' code on this one is 261 B8C (one brown etch over the other). (or possibly k61...these are hard to see even in good light)
This code usually indicates the plate-type,
and/or the inner component style/issue.

The getters are dual-supported circles.

There is a circle and a seriffed 'C' (reversed) on the bottom,
which is 'bathroom etched' rough glass (the C is actually raised casted).

The 'Made in Great Britain' lot number (above) is 163.
(this is always a separate screening from the Mullard logo/name)

And yes,the boxes are also real,
and the boxes alone are worth $50 a set (including wrappings),
both to collectors and fraudulent dealers.

The inner long-plates can't be faked, or any other internals.
(If you can do that, you might as well make brand-new Mullards!).

Typical fakes are either Japanese or Chinese (sometimes Russian or Telefunken) which have been 'silkscreened'.

Quote:

the former Ebay page:

The Tubeking's Guide to NOS and Vintage Audio Tubes
which is still available on Google in Archived pages.
Here's a quote:

"However, you should know which Mullard ECC83 type you are getting, because the sound can differ significantly between each type.

MC1 Long Plate Square Getter: The most sought after, early production and expensive Mullard ECC83 from the mid-1950s. This one has 17mm long gray ladder plates and a dual supported square getter. This is the ultimate 'Mullard' sound.... big, open and warm with a tweedy harmonic overdrive. The etched MC1 code on the bottom of the glass denotes this type, along with the 'B' Blackburn Code + a Number and a Letter.

F91 Long Plate Dual Halo Getter: Similar in sonic characteristics to the MC1 Mullard above. This version comes from the late 50's (roughly 1957-1958) and will sometimes come with a square getter. It sounds very similar or the same to the MC1 Mullard, but is usually a bit less expensive. You can tell this type by the etched F91 code on the bottom of the glass, along with the 'B' Blackburn Code + a Number and a Letter.

F92 Long Plate Single Halo Getter: Similar in sonic characteristics to the F91 Mullard above. This version comes from the late 50's (1959) and will have a single supported halo. It sounds very similar or the same to the MC1 Mullard, but is usually somewhat less expensive. You can tell this type by the etched F92 code on the bottom of the glass, along with the 'B' Blackburn Code + a Number and a Letter.

I61 Short Plate Halo Getter: This is the first short plate Mullard ever produced and was made around 1959-1964. A great tube with that classic 'Mullard' sound, this tube has the benefit of resistance to microphonics due to the plate structure. At the same time, the open 3-D midrange sounds similar to the long plate Mullards, with a little more balls. One of my favorite guitar tubes. You can tell this type by the etched I6I code on the bottom of the glass, along with the 'B' Blackburn Code + two Numbers and one Letter.

I63 Short Plate Halo Getter: This is the second short plate Mullard ever produced* and was made from 1965 onwards. This tube is a bit more compressed than some of the Mullards listed above, so it is favored by many rock guitarists for its distortion characteristics. Many people will use an I61 or F91/F92 tube in the V1 (first slot) of their guitar amp for overall sound, and then put an I63 type in their overdrive slot (usually V2 or V3). This can be an ideal combination, depending on your amp and what you are going for. You can tell this type by the etched I63 code on the bottom of the glass, along with the 'B' Blackburn Code + two Numbers and one Letter. *(There was actually a very short production run "Yellow Label" Mullard ECC83 produced right before this tube.)

CV4004 M187 ECC83 Box plate: The CV4004 box plate Mullard is a military production tube that can be identified by its unique plate structure. This is a well built, highly desirable and favored tube by audiophiles. Many swear by this tube for their home tube stereo systems, and prefer them to regular Mullards. Some guitarists use them in their amps, but most seem to prefer regular Mullards. Produced at the Mullard Mitchum Factory these tubes can usually be identified by the 'R' code etched in the bottom of the glass + a Number and a Letter.

Mullard 10M Master Series ECC83: These were specially made, later production Mullard short plates that are rated for 10,000+ hours in a tube amp. They were also specially selected for low noise and balanced triodes. They can be identified by the Gold Mullard '10M' Logo on the tube and they have gold or regular pins. The Gold Pin versions are superior and worth more. These tubes are highly sought after by audiophiles. They have a wide-band sound similar to a Telefunken, but with a touch of that Mullard warmth. They are quite rare, and can fetch insane prices, especially if they are NOS. I finally got a chance to hear this tube in my guitar amp and I am impressed... fabulous balanced clean sound with a touch of brightness.... incredibly SWEET. Overdrive was pretty cool as well. I can see why audio guys go crazy for these tubes.

There are other Mullard ECC83s that were produced later, but the tubes listed above are the ones you should look for. Beware of fake Mullards being sold on ebay. These will often have 'perfect' baked-on enamel labels that will not wipe off. These labels usually look too thick and 'painted-on' in pictures. Real silk-screened Mullard logos look much more delicate in pictures. Sometimes Matshushita tubes will be sold as Mullards with Shield logos. These are Japanese tubes that were made on Mullard tooling so they look similar to I63 Type Mullards. Not a bad tube, but be aware that some vendors will relabel these to pass them off as the real thing. Sometimes you will see "OEM" Mullards that originally had no labels branded with a fake Mullard label from another era. This can also happen with British 'Brimars' which can have fake Mullard labels. There are also people on ebay selling 'Mullards' with obviously new, fake and cloned 'Mullard' boxes that look nothing like the real thing.... unbelievable. Always purchase your tubes from reputable dealers. We carefully screen each and every tube we sell to make sure they are authentic."

__________________
If you give a man a fish he will eat for a day. But if you teach a man to fish he will buy an ugly hat. And if you talk about fish to a starving man then you are a consultant. Dilbert

I have never seen a genuine Mazda with a seam on top. Seams usually mean Philips equipment, but not necessarily in a Philips factory (e.g. Ei Serbia, BEL India, some Matsushita?).

The ladder anode shape was used by lots of makers. Your valve could be genuine, but it is unlikely to have received its external printing in a Mullard factory. Curious, as the external print is the easiest part for fakers to get right. Maybe, inverting the logic, the dodgy-looking print is a sign of genuineness because only a really incompetent faker would do this?

If I had to guess, I would say this one came from BEL as they were often a bit random with marking. For some reason a late valve has ended up in an early box.

Once at the factory ("Mullard" , "ECC83" etc.)
white, but diluted almost 2%-milky dull and nearly see-thru.

Once presumably after inspection/sorting'Made in Great Britain' (etc.)
This was with a brighter/thicker white, and without careful orientation:
On one tube this was on same side as Mullard labelling,
on the other it was the opposite, and was done probably accidentally,
since the silkscreening was where the 'ECC83' should have been,
but that had been wiped off while still wet,
presumably at the factory by a careless silkscreener.
This led the second printer to place his (G.B.) on the wrong side.

I believe there is great variance in the first printings,
because of the year and/or assigned laborer supposed to do it.

I believe the even greater variance in the "Made G.B." printings
is because these were done later after testing, sorting and shipping,
when they may have been done in different locations,
even from the same batches, after they were distributed and warehoused.

This would be because of 'new' regulations on marking origin of product, which was not carried out consistently
(because it wasn't enforced).

A valve made using Philips equipment could be identical internally to one made in a Philips factory, including anode hole shapes. The 'Mazda fake' you show on the left of your picture in post 5 is unlikely to be made by Mazda, as they did not have top seams. It could be that the Mullard markings on it were put there by Mullard - they sometimes bought in valves from elsewhere but still marked them as Made in Britain.

So my conclusion is that your 'genuine' valve may or may not be genuine, and your 'fake' may or may not be fake. I am astonished to hear that someone might be willing to pay $50 for a genuine Mullard box. I am richer than I thought!